EP3346931B1 - Laparoscopy forceps - Google Patents

Description

The present invention relates to laparoscopic forceps.

Laparoscopy, sometimes referred to as "laparoscopy", is a minimally invasive surgical technique of intervention and diagnosis in human abdominal cavities such as the digestive system, but also in gynecology and urology. It is practiced by means of a plier called "pliers of laparoscopy".

Such laparoscopic forceps are known from which a general and schematic view is illustrated on the figure 1 , for example those described and illustrated in the documents US 5,312,434 and DE 299 11 011 U1 .

Such a clamp comprises a yoke comprising a cylindrical through-bore of revolution defined between a proximal end and a distal end, two jaws with gripping faces, means for mounting in rotation, at the distal end of the through-hole, the two jaws. relative to the yoke around a first axis so that these two jaws are able to take any position between two extreme positions, namely an open position when the two gripping surfaces respectively of the two jaws are between them a non-zero angle and a closed position when the two gripping faces respectively of the two jaws are between them a substantially zero angle.

The clamp further comprises a control rod mounted in translation in the through-hole and defined between a proximal end and a distal end, the proximal end being connected to means for controlling the translation of the rod in the yoke, for example trigger type or the like as illustrated in the figure 1 .

To transform the translation movement of the control rod into rotational movements of the jaws, the clamp comprises pantograph means which connect the distal end of the control rod respectively to the two jaws.

It is also known that such pantograph means essentially comprise two rods, means for rotating the two links, respectively by a first of their two ends, at the distal end of the rod, relative to the control rod and around a second axis, two cams respectively secured to the two jaws by a first of their two ends, the longitudinal axes of these two cams forming between they a substantially zero angle when the two gripping surfaces of the jaws are in contact, means for rotating the second end of each link on the second end of the two cams respectively about a third axis and a fourth axis, the first, second, third and fourth axes being defined so as to be parallel.

Such a laparoscopy forceps gives good results, but may have disadvantages.

In particular, the tongs according to the US 5,312,434 and the DE 299 11 011 U1 have an overall section which is greater than the outer diameter of the yoke, which has the disadvantage of providing a guide tube into which is inserted the yoke of an inner diameter greater than the outer diameter of the yoke. In this case, the yoke is not perfectly guided and the clamp can undergo lateral movements that affect the accuracy of the intervention.

Indeed, as the rods are subject to relatively large forces when the clamp is used, it can happen that they break relatively often, thereby affecting the reliability of the clamp.

Thus, the purpose of the present invention is to provide a laparoscopy forceps which overcomes the drawbacks mentioned above, without being more expensive than the laparoscopic forceps of the prior art, which has a structure corresponding to the two following antagonistic conditions: have a small footprint to be introduced into the human cavities via a guide tube which is actually limited in passage diameter, and which is of maximum strength to achieve the desired operation, for example the removal of a diseased body element, avoiding an in situ rupture of one of the components of the forceps.

• une chape ayant un diamètre extérieur constant sur toute sa longueur fonctionnelle définie entre son extrémité proximale et son extrémité distale, et comprenant une percée traversante cylindrique de révolution définie entre ses extrémités proximale et distale,
• deux mors à faces de préhension,
• des moyens pour monter en rotation, à l'extrémité distale de ladite percée traversante, les deux mors par rapport à ladite chape autour d'un premier axe de façon que ces deux mors soient aptes à prendre toutes positions entre deux positions extrêmes, respectivement une position ouverte quand les deux faces de préhension respectivement des deux mors font entre elles un angle non nul et une position fermée quand les deux faces de préhension respectivement des deux mors font entre elles un angle sensiblement nul,
• une tige de commande montée en translation dans ladite percée traversante et définie entre une extrémité proximale et une extrémité distale,
• des moyens formant pantographe pour lier l'extrémité distale de ladite tige de commande respectivement aux deux dits mors, lesdits moyens formant pantographe comprenant :
  • * deux biellettes,
  • * des moyens pour monter en rotation les deux dites biellettes, respectivement par une première de leurs deux extrémités, à l'extrémité distale de ladite tige, par rapport à la tige de commande et autour d'un deuxième axe,
  • * deux cames respectivement solidaires des deux mors par une première de leurs deux extrémités,
  • * des moyens pour monter en rotation la seconde extrémité de chaque biellette sur la seconde extrémité de chaque came autour respectivement d'un troisième axe et d'un quatrième axe, lesdits premier, deuxième, troisième et quatrième axes étant définis de façon à être parallèles,
    caractérisée par le fait que :
    • le diamètre extérieur de ladite chape ayant une valeur égale à 2D,
    • les biellettes étant identiques et formées chacune d'une plaque à section transversale rectangulaire à bout arrondi, la valeur de la largeur de cette plaque étant égale à 2E,
    • la distance séparant les troisième et quatrième axes de rotation quand les deux faces de préhension des mors sont au contact ayant une valeur 2C inférieure à 2D, et
    • la valeur de l'angle que font les axes des deux biellettes quand les deux faces de préhension des mors sont au contact, étant égale à 2A,
      les valeurs D, E, C et A sont sensiblement liées par l'équation suivante : $$\mathrm{D}=\mathrm{}\mathrm{C}+\mathrm{E}/\mathrm{cosinus\; A},$$
      
      et que
    • le bord extérieur de la seconde extrémité de chaque biellette comporte une partie sensiblement cylindrique chanfreinée d'un rayon sensiblement égal à celui de la surface extérieure de ladite chape de façon que, quand les deux mors sont en position fermée, lesdits moyens formant pantographe soient inscrits dans et sur la surface enveloppante définie par ladite surface extérieure de ladite chape.

More specifically, the present invention relates to a laparoscopic forceps comprising at least:

• a clevis having a constant outside diameter throughout its functional length defined between its proximal end and its distal end, and comprising a cylindrical through-bore of revolution defined between its proximal and distal ends,
• two jaws with gripping faces,
• means for rotating, at the distal end of said through-hole, the two jaws with respect to said yoke around a first axis so that these two jaws are capable of taking any position between two extreme positions, respectively a open position when the two gripping surfaces respectively of the two jaws are between them a non-zero angle and a closed position when the two gripping surfaces respectively of the two jaws are between them a substantially zero angle,
• a control rod mounted in translation in said through-hole and defined between a proximal end and a distal end,
• pantograph means for binding the distal end of said control rod respectively to said two jaws, said pantograph means comprising:
  • * two links,
  • means for rotating the two said links, respectively by a first of their two ends, at the distal end of said rod, with respect to the control rod and around a second axis,
  • two cams respectively secured to the two jaws by a first of their two ends,
  • means for rotating the second end of each link on the second end of each cam about a third axis and a fourth axis respectively, said first, second, third and fourth axes being defined so as to be parallel ,
    characterized by the fact that:
    • the outside diameter of said yoke having a value equal to 2D,
    • the links being identical and each formed of a rectangular cross-section plate with rounded end, the value of the width of this plate being equal to 2E,
    • the distance separating the third and fourth axes of rotation when the two gripping faces of the jaws are in contact having a value 2C less than 2D, and
    • the value of the angle made by the axes of the two links when the two gripping faces of the jaws are in contact, being equal to 2A,
      the values ​​D, E, C and A are substantially related by the following equation: $$\mathrm{D}=\mathrm{}\mathrm{C}+\mathrm{E}/\mathrm{cosine\; A},$$
      
      and
    • the outer edge of the second end of each link comprises a substantially cylindrical chamfered portion of a radius substantially equal to that of the outer surface of said yoke so that, when the two jaws are in the closed position, said pantograph means are inscribed in and on the enveloping surface defined by said outer surface of said yoke.

• La figure 1 est une vue d'ensemble d'une pince de coelioscopie aussi bien selon l'art antérieur que selon l'invention,
• La figure 2 est une vue de principe schématique partiellement en écorché d'une partie de pince de coelioscopie en accord avec la présente invention,
• Les figures 3 et 4 représentent respectivement, pour la figure 3 : une vue en coupe longitudinale schématique de la partie de la pince de coelioscopie industrielle selon l'invention en accord avec la figure 2 qui est une représentation de cette partie à plus grande échelle que sur cette figure 3 et, pour la figure 4 : une vue en coupe transversale référencée IV-IV sur la figure 3 avec en plus un effet de loupe sur la portion entourée de cette figure 4, de façon à bien faire ressortir une caractéristique de l'invention.
• Les figures 5, 6 et 7 représentent, en accord avec les figures 1 à 4, trois vues différentes en perspective cavalière permettant de bien comprendre la structure de la pince de coelioscopie selon l'invention.

Other characteristics and advantages of the invention will appear in the course of the following description given with reference to the accompanying drawings for illustrative but not limiting purposes, in which:

• The figure 1 is an overview of a laparoscopic forceps as well according to the prior art as according to the invention,
• The figure 2 is a schematic principle view partly cut away of a laparoscopic clip part according to the present invention,
• The Figures 3 and 4 represent respectively, for the figure 3 : a schematic longitudinal sectional view of the part of the industrial laparoscopic clamp according to the invention in accordance with the figure 2 which is a representation of this part on a larger scale than on this figure 3 and for the figure 4 : a cross-sectional view referenced IV-IV on the figure 3 with a magnifying effect on the portion surrounded by this figure 4 , so as to highlight a feature of the invention.
• The figures 5 , 6 and 7 represent, in agreement with the Figures 1 to 4 , three different views in cavalier perspective to understand the structure of the laparoscopic forceps according to the invention.

It is first of all specified that, in the present description, if the adverb "substantially" is associated with a qualifier of a given means, without further particular precision, this qualifier must be understood in the strict sense or approached.

The present invention relates, with reference to all the figures, a laparoscopic forceps having at least one clevis 10 having a constant outside diameter over its entire functional length defined between its proximal end 12 and its distal end 13, and further comprising a breakthrough cylindrical throughthrough 11 defined between its proximal end 12 and its distal end 13, such a clevis being generally and very advantageously consists of a cylindrical tube of revolution.

The clamp also comprises two jaws 20, 21 with gripping surfaces 22, 23, optionally toothed as illustrated.

By "gripping face", it is understood, within the meaning of the present description, any surface capable of coming into contact with a given body for, for example, grasping, crushing, cutting, amputating, etc. ..

The clamp further comprises means for mounting in rotation, at the distal end 13 of the through-hole 11, the two jaws with respect to the yoke around a first axis 24 so that these two jaws are able to take all positions between two extreme positions, namely an open position Po when the two gripping surfaces respectively of the two jaws are between them a non-zero angle and a closed position Pf, figures 1 , 2 and 3 when the two gripping faces respectively of the two jaws are between them a substantially zero angle.

There is further provided a control rod 30 mounted in translation Tr in the through-hole 11 and defined between a proximal end 35 and a distal end 31, the proximal end of this control rod 30 being coupled to trigger-type means or the like to control the translation of the control rod into the yoke in the both directions. These latter means are well known in themselves and will not be further described here for the sole purpose of simplifying the present description.

Also provided pantograph means 40 for binding the distal end 31 of the control rod respectively to the two jaws, as more particularly visible on the figure 2 . These pantograph means comprise, in known manner, two links 41, 42, means for rotating the two links, respectively by a first of their two ends, at the distal end 31 of the rod 30, relative to the control rod and about a second axis 32, and two cams 51, 52 respectively integral with the two jaws 20, 21 by a first of their two ends.

These pantograph means further comprise means for rotating the second end of each link 41, 42 on the second end of each cam 51, 52 about a third axis 43 and a fourth axis 44, respectively.

It is further defined that these first 24, second 32, third 43 and fourth 44 axes are all parallel to each other.

• * que le diamètre extérieur de la chape 10 a une valeur égale à 2D,
• * que, les biellettes 41, 42 étant identiques et formées chacune d'une plaque à section transversale rectangulaire à bout arrondi ou équivalent, voir à titre d'exemple la figure 2, la valeur de la largeur de cette plaque est égale à 2E,
• * que la distance séparant les troisième 43 et quatrième 44 axes de rotation quand les deux faces de préhension 22, 23 des mors 20, 21 sont au contact a une valeur 2C inférieure à 2D, et
• * que la valeur de l'angle que font les axes 45, 46 des deux biellettes 41, 42 quand les deux faces de préhension des mors sont au contact est égale à 2A,
  les valeurs D, E, C et A sont sensiblement liées par l'équation suivante : $$\mathrm{D}=\mathrm{}\mathrm{C}+\mathrm{E}/\mathrm{cosinus\; A}.$$
  
  La valeur cosinus A est déterminée par le rapport Z/Y où :
  • Y est la valeur de la distance entre le deuxième axe 32 et l'un des troisième 43 ou quatrième axe 44, et
  • Z est la valeur de la distance entre ce premier axe 32 et là droite passant par les troisième 43 et quatrième 44 axes, quand les faces de préhension 22, 23 sont au contact.

According to an essential characteristic of the invention, knowing:

• * that the outer diameter of the yoke 10 has a value equal to 2D,
• * that, the rods 41, 42 being identical and each formed of a rectangular cross-section plate with rounded end or equivalent, see for example the figure 2 , the value of the width of this plate is equal to 2E,
• * that the distance between the third 43 and fourth 44 axes of rotation when the two gripping surfaces 22, 23 of the jaws 20, 21 are in contact has a value 2C less than 2D, and
• * that the value of the angle that the axes 45, 46 of the two rods 41, 42 when the two gripping surfaces of the jaws are in contact is equal to 2A,
  the values ​​D, E, C and A are substantially related by the following equation: $$\mathrm{D}=\mathrm{}\mathrm{C}+\mathrm{E}/\mathrm{cosine\; A}.$$
  
  The cosine value A is determined by the ratio Z / Y where:
  • Y is the value of the distance between the second axis 32 and one of the third 43 or fourth axis 44, and
  • Z is the value of the distance between this first axis 32 and the straight line passing through the third 43 and fourth 44 axes, when the gripping faces 22, 23 are in contact.

It is specified that the terms "substantially related by the following equation" mean that the value "C + E / cosine A" may be strictly equal to D or very slightly lower, especially because of the "rounded" shape of the ends of the rods.

In addition, since the links are made in rectangular section plates, one of their corner Co, the one corresponding to the outer edge of their second end as shown in the part of figure 4 with magnifying effect, would exceed the outer surface Se of the yoke 10 and would not introduce the clamp in the guide tube.

Also, so that the clamp can be slid into the guide tube, the outer edge of the second end of each link has a substantially cylindrical chamfered portion 80 of a radius substantially equal to that of the outer surface Se of the yoke 10 so that when the two jaws 20, 21 are in the closed position Pf, the pantograph means 40 are inscribed in and on the enveloping surface defined by this surface Se.

Thus, this chamfered portion 80 can easily slide on the inner surface of the guide tube when the clamp is introduced into the guide tube.

The realization of this chamfer is quite possible and does not weaken the rod very little, and in no way the assembly of the rods and cams by the pins 70 as described below.

According to another important and preferred feature of the invention, the two cams 51, 52 are located between the two links 41, 42.

In addition, the means for rotating the second end of a link 41, 42 on the second end of a cam 51, 52 consist of a pin 70 having a pin 71 and a head shoulder 72 secured to the pin rod 71, two cylindrical orifices of revolution 73, 74 coaxially made respectively in the link and in the cam, the cross section of these orifices being substantially complementary to the cross section of the rod of pin 71 so that the latter is able to be inserted slidably in these two orifices, the pin being further plugged into these two holes so that the shoulder head 72 is in contact with the face of the cam which is turned towards the other cam, and means for securing the pin rod 71 only with the rod 41, 42.

The latter means for securing the pin rod 71 with only the rod 41, 42 are chosen from the following means: welding, brazing, gluing, preferably by welding when the materials used for producing the links 41, 42 and pawns 70 allow it. Preferably, therefore, these materials are made of stainless steel or the like.

Very advantageously, the yoke 10 comprises, in the wall of its distal end 13, two open cutouts 61, 62 arranged to allow the passage of the linked ends of the two links 41, 42 and the two cams 51, 52 when the jaws 20, 21 move from the closed position Pf to the open position Po, see for example the illustrations of figures 5 , 6 and especially 7.

When in use, the clamp must be inserted into a guide tube (not shown). The structure of the gripper according to the invention makes it possible to produce a guide tube which has a longitudinal cylindrical through-bore of a diameter substantially equal to the outside diameter 2D of the yoke 10 and advantageously very slightly greater, just necessary to obtain a sliding of the clevis of the pliers in the guide tube.

On the figure 2 , the overall transverse bulk of the two jaws 20, 21 (defined in the plane of the figure 2 ) is shown being lower than that of the two links. But these two dimensions can advantageously be substantially identical and therefore substantially equal to the outer diameter of the yoke 10, as illustrated in FIGS. Figures 3 and 4 .

With the description made above, it appears in particular that the rods may be of maximum width, in any case, for the same application, wider than those of the forceps of laparoscopy of the prior art, which does not It can be conferred on the clamp according to the invention increased reliability, in particular by avoiding a potential rupture of the rods which absorb maximum forces when the clamp is used in laparoscopy.

Claims (6)

1. Laparoscopy forceps comprising at least:

   • a yoke (10) having an outside diameter that is constant over its entire functional length defined between its proximal end (12) and its distal end (13) and having a circularly cylindrical through hole (11) defined between said proximal and distal ends;

   • two jaws (20, 21) having respective grip faces (22, 23);

   • means for mounting the two jaws to the distal end (13) of said through hole (11) to pivot relative to said yoke about a first axis (24) in such a manner that the two jaws are suitable for occupying all positions between two extreme positions, respectively an open position (Po) when the two grip faces of the respective jaws form a non-zero angle between each other, and a closed position (Pf) when the two grip faces of the respective jaws form a substantially zero angle between each other and are substantially in contact;

   • a control rod (30) mounted to move in translation (Tr) in said through hole (11) and defined between a proximal end (35) and a distal end (31); and

   • pantograph-forming means (40) for connecting the distal end (31) of said control rod respectively to both of said jaws, said pantograph-forming means comprising:

   * two links (41, 42);

   * means for mounting said two links via respective first ones of their two ends to the distal end (31) of said rod (30) to pivot relative to the control rod about a second axis (32);

   * two cams (51, 52) secured to respective ones of the two jaws (20, 21) at first ones of their two ends; and

   * means for mounting the second end of each link (41, 42) to the second end of a respective one of the cams (51, 52) to pivot respectively about a third axis (43) and a fourth axis (44), said first, second, third, and fourth axes (24, 32, 43, and 44) being defined so as to parallel,

   • the outside diameter of said yoke (10) having a value equal to 2D;

   • the links (41, 42) being identical, each being formed by a plate of rectangular cross-section with rounded ends, the width of said plate being equal to 2E;

   • the distance between the third and fourth pivot axes (43 and 44) when the two grip faces (22, 23) of the jaws (20, 21) are in contact in closed position (Pf) having a value 2C that is less than 2D; and

   • the angle between the axes (45, 46) of two links (41, 42) when the two grip faces of the jaws are in contact being equal to 2A;
   the values D, E, C, and A being substantially associated by the following equation: $$\mathrm{D}=\mathrm{}\mathrm{C}+\mathrm{E}/\mathrm{cos\; A}$$

   

   characterized by the fact that:

   • the outer edge at the second end of each link has a substantially chamfered cylindrical portion (80) of radius substantially equal to the radius of the outer surface (Se) of said yoke (10) so that, when the two jaws (20, 21) are in the closed position (Pf), said pantograph-forming means (40) are inscribed in and against the envelope surface defined by said outer surface (Se) of said yoke (10).
2. Laparoscopy forceps according to claim 1, characterized by the fact that the two cams (51, 52) are situated between the two links (41, 42).
3. Laparoscopy forceps according to claim 2, characterized by the fact that the means for mounting the second end of a link (41, 42) to pivot relative to the second end of a cam (51, 52) are constituted by:

   - a peg (70) comprising a peg shank (71) and a shoulder-forming head (72) secured to said peg shank (71);

   - two circularly cylindrical orifices (73, 74) made on a common axis respectively in the link and in the cam, the cross-section of said orifices being substantially complementary to the cross-section of said peg shank (71) so that the shank can be engaged slidably in the two orifices, said peg being engaged in the two orifices in such a manner that said shoulder-forming head (72) is in contact with said cam; and

   - means for securing said peg shank (71) to said link (41, 42).
4. Laparoscopy forceps according to claim 3, characterized by the fact that the means for securing said peg shank (71) to said link (41, 42) are selected from the following means: welding; brazing; adhesive.
5. Laparoscopy forceps according to any preceding claim, characterized by the fact that the yoke (10) includes, in its distal end (13), two open-ended slots (61, 62) arranged so as to pass the connected-together ends of the two links (41, 42) and the two cams (51, 52) when the jaws (20, 21) go from the closed position (Pf) to the open position (Po).
6. An assembly, characterized by the fact that it comprises laparoscopy forceps according to at least one of the preceding claims and a guide tube having a cylindrical through longitudinal hole of diameter substantially equal to the outside diameter of said yoke (10).

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